The present disclosure relates to a bypass switch, and more particularly, to a bypass switch having a vacuum interrupter in which a movable contact is moved to a fixed contact to be contacted with the fixed contact.
A bypass switch is installed in an electronic device such as converter. If an abnormality such as a failure occurs, the bypass switch is short-circuited, to minimize influence caused by the failure on other components installed in the electronic device.
The bypass switch may be provided in a converter used in a high voltage direct current (HVDC) transmission system, or may be provided in a static synchronous compensator (STATCOM) or a static var compensator (SVC). The bypass switch may be used as a high-speed short-circuit bypass switch that is short-circuited at high speed.
The HVDC transmission system is a transmission system in which, after a transmission site converts AC power produced at a power station into DC power and then transmits the DC power, a reception site re-converts DC power into AC power and then supplies power.
The STATCOM is a device that is used as a reactive/active power compensator in a power system when electricity is transmitted/distributed, and increases stability by compensating for a loss voltage.
The bypass switch may be provided in a converter including a combination of a plurality of sub-modules. In this case, if an abnormality such as a failure of a sub-module is detected, the bypass switch allow the sub-module of which failure is detected to be short-circuited, so that it is possible to prevent influence caused by the failure on adjacent other sub-modules.
The failure of the sub-module may be detected when there is no feedback signal from the sub-module, when a voltage of a designed value or more is applied to the sub-module, when a communication function of the sub-module is abnormal, when a driver of the sub-module is false, and the like.
The bypass switch may include a movable contact and a fixed contact. The bypass switch may further include a first bus-bar connected to the fixed contact and a second bus-bar connected to the movable contact. If an external force is applied to the movable contact, the movable contact is moved to the fixed contact to be contacted with the fixed contact.
The bypass switch may further include a drive source that generates a drive force for moving the movable contact. When the drive source is driven, the movable contact is moved to the fixed contact to be contacted with the fixed contact.
When the contact between the movable contact and the fixed contact occurs as the drive source is driven as described above, current may flow through the first bus-bar, the fixed contact, the movable contact, and the second bus-bar, and the bypass switch may be short-circuited.